Various stationary induction apparatuses, such as reactors, voltage transformers, current transformers, and similar, comprising a coil and a core, are in use today. For example, reactors are connected to step-up circuits, inverter circuits, active filter circuits, and various other electrical circuits, in which the inductive reactance is used; reactors with various structures have been developed for diverse applications. Many reactors have a coil and core housed within a metal case with other insulating members or similar, in a structure which is packed with resin.
When a reactor housing a core and coil in a case is to be packed with resin, the core and coil must be reliably fixed with respect to the case. As one such mechanical structure, devices using a plate-shape spring member are known. For example, in the technology of Patent Document 1, a leaf spring with a U-shape cross-section is inserted between one side face of the core and an inner side face of the case, and by impelling one side face of the core in a horizontal direction by means of this leaf spring, the core is pressed against the case inner wall and fixed. And, in the technology of Patent Document 2, a plate-shape fitting called a retainer is positioned so as to press from the upper portion of the core in the vertical direction, and is fixed by connection of both ends with bolts to the case.
Patent Document 1: Japanese Patent Application Laid-open No. 2005-72198
Patent Document 2: Japanese Patent Application Laid-open No. 2004-241475
However, in the above-described technologies of the prior art, the direction in which the core is fixed is a single direction, so that there is the possibility of shifting or similar in directions in which the core is not fixed. In order to address this problem, it is conceivable that, in Patent Document 1 for example, a member may be provided separately for fixation from the vertical direction, and in Patent Document 2, a member may be provided separately for fixation from the horizontal direction. However, these methods entail an increase in the number of components and an increase in the number of assembly processes.
In particular, when a leaf spring or similar is to be reliably fixed with respect to the case, bolts must be fastened at a plurality of locations. However, in this case a plurality of bolts are necessary, and moreover a plurality of boss shapes for bolts must be provided in the case.
Further, in the above-described technology of the prior art, the core and coil are housed within a case, and after fixing with a leaf spring, packing with resin is performed. However, because the leaf spring has a thin plate shape, there is a large amount of space within the case other than the leaf spring, and the amount of resin packed is increased. Such an increase in the amount of packed resin results in increased manufacturing costs when the resin is comparatively expensive (as in the case of urethane resins, for example). In particular, when using a design in which there is pressing from above by a retainer as in Patent Document 2, there is still more space within the case, and costs are increased.
Further, when using a leaf spring for pressing, there is contact with the core in a linear area or a narrow area. Hence when using a laminated core or similar, manufactured by laminating silicon steel sheets or other materials, there is the possibility of local concentration of excessive force along the lamination direction.